潜水埋深对疏叶骆驼刺(Alhagi sparsifoli)幼苗生长和叶片形态的影响

研究了潜水埋深(40、80、120、180、220cm)处理对一年生疏叶骆驼刺(Alhagi sparsifoli)幼苗生长和叶片形态的影响。结果表明:随着潜水埋深的增加,疏叶骆驼刺幼苗叶片厚度逐渐增加,叶片厚度在220cm埋深下最大,长度和宽度在120cm埋深下最大,且叶片长度呈优先减小的趋势;潜水埋深变化对疏叶骆驼刺株高生长影响不大,但对冠幅和分枝数的生长影响显著(p0.05);除40cm埋深处理中根系以平均1.24cm·d-1的速率扎入地下水层外,其他4个处理根系生长速率随潜水埋深的增加而增加,且180cm和220cm埋深下根系生长速率明显高于其他3个处理;根系到达220cm潜水埋深的时间为123d;幼苗生物量积累随着潜水埋深变化先增加后减小,茎叶生物量在120cm埋深处理中达到最大值,而根系生物量在180cm埋深下最大。潜水埋深变化对疏叶骆驼刺地上部分和根系生长的影响不同,潜水埋深增加有利于根系生长和根系生物量增加;以120cm为拐点,潜水埋深过浅或过深都会抑制地上部分生长;220cm潜水埋深条件下,疏叶骆驼刺生长缓慢且生物量的累积最小,表明若潜水埋深大于220cm则对幼苗生长不利。

Effects of Water Table Depth on Leaf Morphology and Growth of Alhagi sparsifolia Seedlings

The seedlings of Alhagi sparsifolia were chosen as the experimental materials, and five groundwater table treatments (40, 80, 120, 180 cm and 220 cm) were proceeded to analyze the influences of increasing phreatic water depth on the leaf morphology and growth of Alhagi sparsifolia seedlings. The results are as follows: With the increase of water table depth, the leaf thickness increased gradually and reached the maximum under the treatment of 220 cm. The leaf length and width increased firstly and then decreased, they both reached the maximum under the treatment of 120 cm. Changing water table depth had no significant impact on the height of seedling, but its impacts on the canopy and branch number of seedling were significant (p<0.05). The roots grew and got close to the groundwater with an average rate of 1.24 cm per day under the treatment of 40 cm, and the growing rate of roots under the other treatments increased with increasing ground water depth. The growing rate of roots under the treatments of 180 cm and 220 cm were higher than the other treatments apparently. It took 123 days for the roots to get to the 220 cm water depth. With increase of phreatic water depth, the biomass of seedling increased firstly and then decreased. The maximum biomass of leaf and stem appeared under the treatment of 120 cm, and the maximum biomass of root was under the treatment of 180 cm. The results indicated that the changes of water table depth had different influences on the aboveground part and roots. The increase of ground water table depth helped to increase the length and biomass of roots. The depth of 120 cm could be taken as an crucial point, phreatic water depth deeper or shallower than that point would restrict the growth of the aboveground part. The seedlings had slow growth and the fewest biomasses accumulation under the water depth of 220 cm, suggesting that the groundwater table depth over 220 cm was harmful for the growth of seedling.